What notification message types does MCP support?

MCP supports several notification types that are fire-and-forget messages requiring no response. Progress Notification reports completion status during long operations. Logging Message Notification sends log messages for debugging. Tool List Changed Notification informs when available tools change. Resource Updated Notification signals when a resource is modified. Initialized Notification confirms client setup is complete. Cancelled Notification indicates a request was cancelled. All flow in one direction without acknowledgment.